Each year, more than 380 million metric tons of plastic is produced worldwide. Lego is responsible for 100,000 metric tons of it. This contribution to the annual total is, of course, the result of making its classic children’s toy. Lego’s impact may initially appear to be a sliver of that plastic output, but it still counts. Why? That 100,000 metric tons of polymer was last year turned into 110 billion bricks. 

What’s more, the vast majority of those 110 billion bricks, as much as 80 percent, were made from acrylonitrile-butadiene-styrene, or ABS, a petroleum-based thermoplastic prized for its strength and rigidity. ABS does not like being recycled, because it loses those sturdy qualities. Such is the resilience of ABS, it takes lifetimes to break down, meaning whatever is made from the stuff will be hanging around on our planet for an awfully long time.

This is why, in 2015, after 66 years of pumping out vast quantities of unrecyclable interlocking toy bricks and perhaps sensing the impending plastic backlash, Lego announced it was putting $155 million of its huge income (2019 revenue hit $7 billion) into a new Sustainable Materials Center. 

The first tangible product to come out of this center was a sugarcane-based plastic. It took the company two years to perfect this sustainable polyethylene, and it was hailed as a great success. The trouble was, due to its less-than-rigid nature, it was mainly suited to non-load-bearing lines, like trees and leaves—a tiny proportion of Lego products, around 2 percent. 

Now, however, comes the main event: the humble 2 x 4 brick. Lego has moved on from bendy bioplastic to making a new prototype block that is fabricated from PET plastic from discarded bottles. It is the very first brick made from a recycled material to meet most of Lego’s requirements for its standard ABS bricks. 

Over the past three years, Lego’s 150-strong Sustainable Materials team has tested more than 250 variations of PET materials. The resulting prototype, according to Tim Brooks, vice president of environmental responsibility at Lego, nails one of the toughest hurdles for a non-ABS brick: clutch power.

Clutch power is simply how well two joined bricks stick together. If a plastic is not rigid enough or shrinks too much in the manufacturing and molding process, the Lego blocks simply won’t grip to each other properly. 

“We’re molding to the tolerance of about one to two microns, less than the thickness of a human hair,” says Brooks. “That’s incredibly precise compared to most consumer products. So the clutch is probably the number-one challenge we have. Either prototype bricks simply don’t hold or you’re using pliers to get them apart. To get that brick to mold effectively is hard. To go into the mold in about the consistency of toothpaste—pushing it in warm and then cooling it down – the material will shrink, you need it not to shrink too much.”